This invention relates to an improved digital to analog resolver converter of the type described in pending U.S. Pat. Application Ser. No. 620,740 filed on Oct. 8, 1975, said application having been assigned to the same assignee, The Singer Company, as has this application. The disclosure of U.S. Pat. Application Ser. No. 620,740, is incorporated by reference and made part hereof.
The digital to analog resolver converter uses a conversion technique of approximating sine and cosine functions with linear or chord functions. This approximation results in a systematic error of a magnitude which, for certain purposes, exceeds allowable limits. As a result, an efficient, compact system which would reduce these errors was needed.
The prior art reveals two ways to achieve the necessary converter accuracy. One, precision solid state converters can be constructed utilizing expensive component parts whose combined inaccuracies are within performance objectives. Two, converter performance can be enhanced through error compensation generated by a computer working in conjunction with the converter.
However, both these prior art solutions have serious disadvantages. Precision solid state converters with the desired accuracy are both expensive and bulky. Enhancing converter performance through computer error recognition suffers from the inherent problem of requiring a costly separate computer with available capacity.